The question is asking us to identify the statement that is not true of ECOWAS, which means we need to find the statement that does not accurately describe the organization.
The answer is "non-payment of annual subvention by any member country leads to loss of membership." This statement is not true. Although annual dues are required from member countries to support the organization's activities, failure to pay these dues does not automatically lead to loss of membership. Rather, the organization may impose sanctions or other penalties on the defaulting member country, but expulsion is not automatic.
ECOWAS is an international organization made up of 15 countries in West Africa, and its aim is to promote economic cooperation among member countries. It allows citizens of member countries to stay for at least ninety days within any country, which is intended to promote free movement of people within the region. ECOWAS has been instrumental in promoting regional integration and economic development in West Africa.